Diagnostic modality for evaluation of right ventricle in chronic thromboembolic pulmonary hypertension patients

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive disease of pulmonary hypertension (PH) as a consequence obstructive of pulmonary arteries with thromboembolism. Augmented pulmonary vascular resistance and pulmonary artery pressure (PAP) can ultimately lead to the right ventricular dysfunction, which leads to adaptive and maladaptive changes. Right ventricle (RV) remodeling can cause clinical deterioration and RV failure. Aims and Objectives: We aimed to evaluate the RV functions with a new diagnostic modality 2-deoxy-2-(18F)-fluoro-D-glucose (FDG)-positron emission tomography (PET) in patients with CTEPH. Materials and Methods: We included 53 patients diagnosed with CTEPH who were planned to have pulmonary thromboendarterectomy (PEA) and did not have any contraindication for cardiac PET/computed tomography (CT). We performed transthoracic echo, cardiac PET/CT, 6-minute walk distance (6-MWT), and right heart catheterization 1 week before PEA surgery. Results: The patients divided into two groups according to RV/left ventricle (LV) FDG-PET uptake ratio, RV/LV ≤1, and RV/LV >1. Six-MWD was significantly higher in the RV/LV ≤1 group (P = 0.005). Pro-BNP was considerably higher in the RV/LV >1 group (P = 0.041). Conclusion: The present study aims to demonstrate the RV/LV FDG-PET uptake ratio could be used in the noninvasive diagnostic method in diagnosing, treatment strategy, and clinical follow-up in patients with CTEPH.